The present invention relates to an apparatus for detecting an amount of a liquid contained in a bottle to be delivered by a delivery nozzle, and more particularly to an apparatus for detecting amounts of different kinds of reagents remaining in reagent vessels for use in an automatic chemical analyzer.
Various types of automatic chemical analyzers have been developed and practiced. They may be roughly classified into two types on account of a manner of treating one or more reagents. In the first type of analyzer, required reagents are set in the analyzer every day, and in the second type of analyzer the reagents are reserved in a refrigerator installed in the analyzer. Recently, the second type of analyzer has become popular because the reagents can be handled or managed easily. In such an analyzer, it is necessary to monitor or detect amounts of the reagents remained in reagent bottles at the beginning of an analysis or during the analysis, and when a residual amount of a certain reagent is detected to become smaller than a predetermined minimum amount, it is necessary to supplement a new reagent. For instance, Japanese Patent Application Laid-Open Publication No. 2,966/80, discloses an apparatus for detecting an amount of a residual reagent in a reagent bottle. This known apparatus comprises a detecting float to be put in the reagent bottle and two arrays of detector groups which detect a position of the float in the reagent bottle. This apparatus has drawbacks in that the construction is complicated and it is not suitable for detecting a small amount of the residual reagent. Particularly, in a multi-item analyzer in which a plurality of reagents are set for effecting a plurality of test items, there must be provided a plurality of the detecting apparatuses and thus, the construction becomes further complicated.